Ballast water is loaded in ports by ships and stabilizes a ship when it is not carrying a cargo. With the ballast water follows native species of aquatic flora and fauna which are discharged with the ship's ballast water into a new environment when the ship loads cargo in a new port. Some of these organisms may survive become invasive and threaten the native ecology around the new port and even spread diseases such as cholera. Local economic activities such as fisheries may be threatened by these activities. Annual losses incurred on economy as a result of the spread of invasive species are staggering and estimated in the EU at more than 30 billion Euros annually. In the U.S. the annual losses are estimated at more than 50 billion USD.
To eliminate or at least minimize the risk of new introductions of invasive species the International Convention for the Control and Management of Ship's Ballast Water and Sediments was adopted in 2004. The Ballast Water Management Convention requires vessels in international traffic to treat their ballast water and meet certain quality criteria before discharging the water. This requirement has fuelled the development of ballast water management systems (BWMS) to allow on-board treatment of the ballast water for the maritime vessels.
However, there remains a need for a system for monitoring the quality of ballast water to ensure compliance with the above-mentioned quality criteria. The system for monitoring the quality of ballast water should preferably allow for safe and energy efficient treatment of the ballast of the vessel.
U.S. patent application No. 2003/0176971 discloses a ballast water monitoring system for tracking the exchange of ballast water in the ballast water tank of a ship. The system comprises an on-board ballast water analysis system, as, which comprises a chemistry probe that may detect the chemical composition of the ballast water contained within the ballast water tank such as its salinity and amount of explosives, illegal drugs, biological agents etc. The ballast water monitoring system furthermore comprises a remote central data management unit (remotely located internet central server) which receives ballast water data and accompanying geographical location information from a plurality of ships. The central server is used to organize and disseminate the chemistry tracking data collected from a large number of ships. The central server may be coupled to the on-board ballast water analysis system through the Internet, or wirelessly via a cellular or satellite telephone modem. The governmental authorities can verify that the exchange of ballast water takes place outside the 200 nautical miles Exclusive Economic Zone, as regulations state. In the preferred embodiment of the invention, the salt content of ballast water is detected and when a change in salt content of the ballast water exceeds a pre-determined threshold, the geographic location of the ship is determined for example by GPS. A set of data representing this information is transmitted to the remotely located internet central server.
U.S. Pat. No. 7,890,226 discloses an emission management system for a vessel. The emission management system includes a monitoring assembly for monitoring an emission from the vessel. The monitoring assembly is adapted to automatically detect the emission from the vessel and generate a data set representative of a vessel location at a time the emission occurred. The emission management system also includes a data storage system in communication with the monitoring assembly for recording the data set generated by the monitoring assembly. In one embodiment the emission management system is adapted to treat and monitor the ballast water of the vessel. The emission management system may comprise a treatment device and emission sensor which is adapted to determine the concentration or quantity of contaminants in the treated ballast water.
U.S. 2005/0016933 discloses apparatuses and methods of a ballast water treatment system for a vessel. The ballast water treatment system includes a control system and a ballast tank system. The control system controls a concentration of a biocide in the ballast tank system. The control system is capable of controlling the concentration of a biocide in the ballast tank system by controlling the amount of the biocide feed into the ballast tank system from the biocide generation system. Parameters of the control system, such as the concentration of residual biocide, can be set by the user to treat different types of ballast water differently and/or comply with local, state, federal, and/or international regulations.